Buggy code:
public class FileListActivity extends AppCompatActivity implements IItemListViewContainer { public static final String KEY = "com.lasthopesoftware.bluewater.servers.library.items.media.files.list.key" ; public static final String VALUE = "com.lasthopesoftware.bluewater.servers.library.items.media.files.list.value" ; public static final String VIEW_ITEM_FILES = "com.lasthopesoftware.bluewater.servers.library.items.media.files.list.view_item_files" ; public static final String VIEW_PLAYLIST_FILES = "com.lasthopesoftware.bluewater.servers.library.items.media.files.list.view_playlist_files" ; private int mItemId ; private ProgressBar pbLoading ; private ListView fileListView ; private ViewAnimator viewAnimator ; private NowPlayingFloatingActionButton nowPlayingFloatingActionButton ; @ Override public void onCreate ( Bundle savedInstanceState ) { super . onCreate ( savedInstanceState ) ; getSupportActionBar ( ) . setDisplayHomeAsUpEnabled ( true ) ; setContentView ( activity_view_items ) ; fileListView = ( ( ListView ) ( findViewById ( lvItems ) ) ) ; pbLoading = ( ( ProgressBar ) ( findViewById ( pbLoadingItems ) ) ) ; fileListView . setVisibility ( INVISIBLE ) ; pbLoading . setVisibility ( VISIBLE ) ; if ( savedInstanceState != null ) mItemId = savedInstanceState . getInt ( FileListActivity . KEY ) ; if ( ( mItemId ) == 0 ) mItemId = this . getIntent ( ) . getIntExtra ( FileListActivity . KEY , 1 ) ; setTitle ( getIntent ( ) . getStringExtra ( FileListActivity . VALUE ) ) ; final TwoParameterRunnable < FluentTask < String , Void , List < IFile > > , List < IFile > > onFileProviderComplete = new TwoParameterRunnable < FluentTask < String , Void , List < IFile > > , List < IFile > > ( ) { @ Override public void run ( FluentTask < String , Void , List < IFile > > owner , List < IFile > result ) { if ( result == null ) return ; final LongClickViewAnimatorListener longClickViewAnimatorListener = new LongClickViewAnimatorListener ( ) ; fileListView . setOnItemLongClickListener ( longClickViewAnimatorListener ) ; final FileListAdapter fileListAdapter = new FileListAdapter ( FileListActivity . this , id . tvStandard , result , new ItemListMenuChangeHandler ( FileListActivity . this ) ) ; fileListView . setAdapter ( fileListAdapter ) ; fileListView . setVisibility ( VISIBLE ) ; pbLoading . setVisibility ( INVISIBLE ) ; } } ; getNewFileProvider ( ) . onComplete ( onFileProviderComplete ) . onError ( new com . lasthopesoftware . bluewater . servers . connection . HandleViewIoException < String , Void , List < IFile > > ( this , new Runnable ( ) { @ Override public void run ( ) { getNewFileProvider ( ) . onComplete ( onFileProviderComplete ) . onError ( new com . lasthopesoftware . bluewater . servers . connection . HandleViewIoException < String , Void , List < IFile > > ( FileListActivity . this , this ) ) . execute ( ) ; } } ) ) . execute ( ) ; <START_BUG> nowPlayingFloatingActionButton = NowPlayingFloatingActionButton . addNowPlayingFloatingActionButton ( ( ( RelativeLayout ) ( findViewById ( rlViewFiles ) ) ) ) ; <END_BUG> } private FileProvider getNewFileProvider ( ) { } @ Override public void onStart ( ) { } @ Override public void onSaveInstanceState ( Bundle savedInstanceState ) { } @ Override public void onRestoreInstanceState ( Bundle savedInstanceState ) { } @ Override public boolean onCreateOptionsMenu ( Menu menu ) { } @ Override public boolean onOptionsItemSelected ( MenuItem item ) { } @ Override public void onBackPressed ( ) { } @ Override public void updateViewAnimator ( ViewAnimator viewAnimator ) { } @ Override public NowPlayingFloatingActionButton getNowPlayingFloatingActionButton ( ) { } }

Fix:
nowPlayingFloatingActionButton = NowPlayingFloatingActionButton . addNowPlayingFloatingActionButton ( ( ( RelativeLayout ) ( findViewById ( rlViewItems ) ) ) ) ;